Method and apparatus for rounding



Sept. 2, 1924. A

G. E. M IRFIELD A l A um' DDDDDDDDD Ank uuuuuuuuuuuu NG Patented Sept. 2, 1924. i if i l Y N.UNITED STATES? Y GEORGE E. MIRFIELD,l or YoUNGsTowN, ionic. .t

METHOD vAnnV APPARATUS non noUNDIGI l. 'i l *Application led July 11,

' method and apparatus for rounding circulai' objects, such as pipesandthe like.

Itslias heretofore been customary in the art to which the present invention relates to expand and round pipes and similar oby jects by supporting the same between meinbers adapted to encircle and engage the major portion of the periphery7 thereof'and then subject the interior of the pipe to anv expanding operation. This is in the nature of a spinning operation, but has not provenv altogether satisfactory due tothe difficulty' of producing an accurately roundedriinished product.-

I have .discovered that the Vditliculties Y which 'have heretofore been encountered-in this particular art may be obviated by modi-'- fying the construction of the supportingA members in suoli manner Vaslto permit flexing of the walls of the pipe during the rounding operation. .f

-In the accompanyingdrawings,there is shown for purposes 'of illustration-only one" embodiment of my invention, it being understood that the drawings do not define'the limits of my `invention. and that changes maybe made inthe constructionand ope-ra-l tion disclosed herein without departing from` the spirit of.my-inventionfor scope-of fmy broader claims. In the drawings, l Figure 1 is a longitudinalfsectional viewV through a portion of a pipe to be rounded,- the supporting members andthe' expander;A Figure 2- is a transverse sectiona'lview on the line VII-IIof Figure 1,:and l Figure `3 is atop iplan-iview ofthe-exA pander.. r 'Y' In tlierillustrated embodiment of1myinvention,-there isdisclosed a pair 'of opposed supporting members 2'- adapted f lto l engage and extendzaround substantiallyA the entire circumference of? the object tol-be rounded;-

These supporting .members mayconveniently be moved toward and:away?'froiiithe2 surface of .the .pipe V3 to :befi'ou'ndedby isza lserial 'no'. 574,184'.

tion, and 'the `members may beA guided by@ plates 5 v between which` providing `suitable they are movable.'

4"'It'fli'as heretoforebeen customary to pro-y vides'uch supporting members with abuni-V formly curvedV supporting vsurface'having a',

curvaturefveither Vcorresponding to orv slightly greater than Vthe curvature of the outer su-rfaceof'the article toV be rounded. In

accordanoe'withthe present invention, liow-` ever, thev supporting surfaces of the-members 2 are each` provided witha series'of spaced engaging portions 6, preferably Vproviding line contacts, whereby the pipe or other are ticle be'eingeperatedr upon will be gripped at a f' plurality of `circumferentiallylspaced Y points, Ythereby` permitting support.v

`For exerting an expanding action on the article being rounded I may providea rotary traveling expanding device comprising a move thefnfiandrel 9.to the right as'viewed in Figurel 1.

end'the tapered may be formed in p 'flexing of theV Y' walls` of lthe article betwee Ythe points ofV v"Coopei'lav-tiiig.witlithe mandrel 9 and 'eX-ri tendingtherearoundf isa carrier 12 having` Aformed therein a series of radially .extending openings'iv'l eachyadapted t receive'an eir-` pending roller 14. The longitudinal axes oftheope'nings 13 pre'ferably'exteiid 'at an l a'iigle7to-1the longitudinal'axis of the stem '8,1

asv clearly showiiiii Figure 3. f Due to this construction,- it vwill be apparent Vvthat the rollers 14 also extend latY a similarangle.

The-'carrier-*IQ maybe-formed withia re duced h'ub portion=15 adapted to extend into" therecess 110 and beeiigagedby al second com# pressionfspring 116f `located' there-ini The carrier m'ayf beheld againstfremoval by pro-k viding vaset screw or other similar means V1'? for engaging the hub portion thereof. Vf. *The Y iamountVV off movement imparted to then'iandrel 91 by th'ejaction of the spring 11 mayk beY 1 regulatedV by' providing a suitable adjustinginutlS ontlie'v stemS. Forv withdra-Wingjthe-mandrel against the action of the vvspringll" there: maybe provided van operating pin 19 extending through4 slot 2O in the headl and permitting the' stemv and screw downs tofranvweliknown construcLf mandrel -tobe bodily moved longitudinally pipe or other article to be rounded and rela-V tive rotation between the expander and-said article may be produced Vin any desired manner. In some cases it will be apparent that it will be desirable to rotate the supporting members and the article 3 relatively to the expander while in other cases it will vbe desirable to maintain the supporting members stationary and rotate the expander within the article being operated upon. In either of these cases, the rollers 14 will tend to move into the end of the article due to the angular extension of their axe-s, and will exert a gradually increasing and dev creasing pressure successively on successive portions of the article being rounded. During this operation, the rollers will also be expanded outwardly against theinner sui'- ace of the article .by the action` of the tapered mandrel 9, and during the relative rotation will tend to ile-x the wallsot theV article between the spaced points ot support- This provides for the requisite movement of said walls and enables an accurately rounded product to be formed. f

Y It will be' apparent to those skilledin the art that the present invention lends itself admirably to usewith pipe cutting, rounding and threading machines ot' standard constructions and enablesA the ends of the pipes to be rounded before the threading operation occurs. y i v The advantages of the present invention arise from the provision of means for and the method of supporting the article Yto plurality of spaced line contacts with the.

surface of the article and then subjecting the wall of the article between the lines of support to a succession of substantiallyl' uniformv bending pressures to' round ,the saine, substantially as described..v

apted to engage `an to conform to the. contour of the holding M means, substantially as described.

5. In the method of rounding a pipe, theY steps consisting in supporting the pipe at a plurality o't' circumferent-ially spaced points, and subjecting the walls of the pipe between the points of Support to a succession of substantially uniform bending pressures to round the same, substantiallyas described.

6. In the method of rounding a pipe, the steps consisting in initially holding the pipe at a plurality of circumferentially spaced points, applying a bending pressure to the walls of the article in opposition to the pressure of the holding points to flex the walls lof the article between said points, and producing a relative rotational movement between the article and the pressure exerting means, substantially as described.

7. In themethod of rounding a pipe, the steps consisting niinitially holding the pipe at a plurality of circumferentially spaced points, and applying a succession of bending pressures to the walls of the article in opposition to the pressure of the holding points to flex the walls of the article between said points, substantially as described. Y

8. In an apparatus for. rounding metal articles, means for supporting the article to be rounded at a plurality of'spaced points, be rounded at a plurality olf-spaced points whereby flexing of the walls, thereof mayl and means for successively exing the walls of the pipe intermediate the points of sup-- port toround the same, substantially as de'- scribed.

t 9. In an apparatus for rounding metal articles, means orsupporting the article atV a' plurality of points el'ective'radially thereof, and means for gradually flexing the walls of the pipe to round the same by subjecting 4the walls to gradually increasing and decreasing pressures, substantially as described.

l0. In an apparatus `for rounding .icylini drical articles, means for' supporting the. article in a plurality'of radial planes, andv means for successively flexing the walls of the articlebetween different points of support, substantially as described. V

11."` In -anfapparatus for rounding cylin- In the method of rounding a hollow dricalarticles, .means p roviding` a plurality of spaced line contacts for the article and means for successively flexing thev wall of the article between differentV contacts, substantially as described. Y

12. 1n an apparatus for rounding pipe, means for supporting the pipe to permit flexing of the walls thereof, and means exerting a gradually increasing and then decreasing pressure in opposition to said supporting means for flexing said walls, substantially as described.

13. In an apparatus for rounding pipe, means providing a plurality of spaced pipe supporting portions permitting flexing of the walls of the pipe therebetween, and expanding means adapted to exert flexing pressure at separated points in opposition to. said supporting means, and means for producing relative rotational movement between the pipe and said last mentioned means, substantially as described.

14. In an apparatus for rounding pipe, a plurality of pipe supporting members each having a plurality of spaced pipe engaging portions formed thereon, and means for'successively flexing the walls of the pipe intermediate successive points of support, substantially asdescribed.

15. A pipe supporting means comprising a supporting member having a plurality of supporting means suiiciently spaced to permit flexing therebetween of a wall of a pipe supported thereby and means gradually effective from 011e supporting means to the y next for flexing the pipe walls, substantially ly engaging adjacent portions of a sup-A ported article, substantially as described. 17. In the method of rounding metal articles, the steps consisting of substantially uniformly supporting the article and then.

successively flexing different portions of the walls thereof, substantially as described.

18. In the method of rounding hollow articles, the steps consisting of substantially y uniformly Vsupporting'the article and then successively and substantiallyV uniformly flexing successive portions Vof, the walls thereof, substantially as described.

' 19.111 the method of rounding pipes, the

steps consisting ofsupporting a pipe to per- ,Y Vmit flexing of portions of thev wall of theVv pipe between definitely located supporting and pipe engaging means, and then successively flexing said portions, substantially as described.

Intestimony whereof I have hereunto set my hand.

l GEORGE E. MIRFIELD. 

